EP1986776B1 - Irregularly shaped, non-spherical supported catalyst and process for hydroconversion of heavy petroleum fractions - Google Patents

Abstract

The present invention concerns a catalyst for hydrotreating and/or hydroconverting heavy metal-containing hydrocarbon feeds, said catalyst comprising a support in the form of mainly irregular and non-spherical alumina-based agglomerates the specific shape of which results from a crushing step, and containing at least one catalytic metal or a compound of a catalytic metal from group VIB and/or group VIII (groups 8, 9 and 10 of the new periodic table notation), optionally at least one doping element selected from the group constituted by phosphorus, boron and silicon (or silica which does not form part of that which may be contained in the selected support) and halogens, said catalyst essentially being constituted by a plurality of juxtaposed agglomerates each formed by a plurality of acicular platelets, the platelets of each agglomerate generally being oriented radially with respect to each other and with respect to the centre of the agglomerate. The specific shape of the catalyst improves its performance when using it for hydroconverting/hydrotreating heavy metal-containing hydrocarbon feeds. The invention also concerns the use of said catalyst alone or as a mixture in a fixed bed or ebullated bed reactor.

Description

Technical area

The present invention relates to a catalyst that can be used for the hydrotreatment and / or hydroconversion of heavy hydrocarbon feedstocks containing metals, said catalyst comprising a support in the form of agglomerates based on alumina, predominantly irregular and non-spherical, the specific form of which results from a crushing step, and comprising at least one catalytic metal or a Group VIB catalytic metal compound (group 6 of the new notation of the periodic table of the elements), and / or at least one catalytic metal or a compound catalytic metal group VIII (group 8, 9, and 10 of the new notation of the periodic table of elements), optionally at least one doping element selected from the group consisting of phosphorus, boron, silicon (or silica that does not belong to that which could be contained in the chosen support) and halogens, said catalyst consisting essentially of a plurality and the juxtaposed agglomerates each formed of a plurality of acicular plates, the platelets of each agglomerate being oriented generally radially relative to one another and to the center of the agglomerate. The specific form of the catalyst gives it improved performances in its implementation for the hydroconversion / hydrotreatment of the charges containing metals.

PRIOR ART

It is known to one skilled in the art that during hydrorefining and / or hydroconversion reactions of petroleum fractions containing organometallic complexes, most of these complexes are destroyed in the presence of hydrogen, hydrogen sulphide, and a hydrotreatment catalyst. The constituent metal of these complexes then precipitates in the form of a solid sulphide which is fixed on the inner surface of the pores. This is particularly the case of vanadium complexes, nickel, iron, sodium, titanium, silicon, and copper which are naturally present in crude oils in greater or lesser abundance depending on the origin of the oil and which, during the distillation operations, tend to concentrate in the higher boiling fractions and in particular in the residues. This is also the case of coal liquefies which contain metals, in particular iron and titanium. The general term hydrodemetallation is used to refer to the reactions of destruction or disintegration of organometallic complexes in hydrocarbons.
The accumulation of solid deposits in the pores of the catalyst can continue until the complete blockage of a portion of the pores controlling access of the reagents to a fraction of the interconnected porous network such that this fraction becomes inactive even though the pores of this fraction are only slightly cluttered or even intact. This phenomenon can therefore cause a premature and very important deactivation of the catalyst. It is particularly sensitive in the case of hydrodemetallation reactions in the presence of a supported heterogeneous catalyst. By heterogeneous is meant non-soluble in the hydrocarbon feed. In this case, it is found that the pores of the periphery clog faster than the central pores. Similarly, the mouths of the pores are clogged faster than their other parts. The obstruction of the pores goes hand in hand with a progressive reduction of their diameter, which leads to an increased limitation of the diffusion of the molecules and an accentuation of the concentration gradient, thus an accentuation of the heterogeneity of the deposit from the periphery towards the porous particles to the point that complete obstruction of the externally opening pores occurs very rapidly: access to the almost intact internal porosity of the particles is then closed to the reactants and the catalyst is prematurely deactivated.

The phenomenon just described is well known as clogging the mouths of pores. The evidence of its existence and the analysis of its causes have been published several times in the international scientific literature.

A hydrotreatment catalyst of heavy hydrocarbon cuts containing metals must therefore be composed of a support having a porosity profile, a porous structure and a shape (geometry) particularly adapted to intragranular diffusion constraints specific to hydrotreatments to avoid clogging problems. mentioned above.
The catalysts usually employed are in the form of beads or extrudates and are composed of a support based on alumina having a particular porosity and an active phase based on mixed sulphides consisting of both a sulphide of a Group VIB metal (preferably molybdenum) as well as a group VIII metal sulfide (preferably Ni or Co). The metals are deposited in the oxide state and are sulfided to be active in hydrotreatment. The atomic ratio between the element of group VIII and the element of group VIB considered as optimal usually is between 0.4 and 0.6 atom group VIII / atom group VIB. Recently, it was shown in the document EP 1 364 707 A1 ( FR 2 839 902 that, independently of the porous texture, a ratio of less than 0.4 makes it possible to limit the deactivation of the catalysts and thus to extend the life of the catalysts.

It is known to those skilled in the art that there are two types of alumina-based support hydrorefining catalysts and / or hydroconversion of heavy hydrocarbon feeds containing metals. These supports are distinguished at first by their porous distribution profiles.

Catalysts with a bimodal porosity profile are very active, but have a lower retention capacity than catalysts with a polymodal porosity profile.

The polymodal porosity profile corresponds to a cumulative distribution curve of the pore volume as a function of the pore diameter obtained by the mercury intrusion method which is neither monomodal nor bimodal, in that it does not appear distinct pore families whose pore diameters are centered on well-defined average values, but a relatively continuous distribution of pores between two extreme diameter values. Between these extreme values, there is no horizontal plateau on the porous distribution curve. This polymodal distribution is linked to a porous structure of "chestnut bug" or "sea urchin" obtained with agglomerates of alumina prepared by rapid dehydration of hydrargillite then agglomeration of the flash alumina powder obtained according to a patent of the plaintiff ( US 4,552,650 FR-A-2,528,721 - IFP). The alumina agglomerates thus prepared can be in the form of beads or in the form of extrudates as shown by the patents FR 2,764,213 and US 6,043,187 .
The structure "chestnut bug" or "sea urchin", consists of a plurality of juxtaposed agglomerates each formed of a plurality of acicular plates, the plates of each agglomerate being oriented generally radially vis-à-vis -vis others and compared to the center of the agglomerate. At least 50% of the needle-shaped platelets have a dimension along their axis of greater development of between 0.05 and 5 microns and preferably between 0.1 and 2 microns, a ratio of this dimension to their average width of between 2 and 20 microns. , and preferably between 5 and 15, a ratio of this dimension to their average thickness of between 1 and 5000, and preferably between 10 and 200. At least 50% of the acicular plate agglomerates constitute a collection of pseudo-spherical particles of average size between 1 and 20 micrometers, preferably between 2 and 10 micrometers. Very suitable images to represent such a structure are a lot of thorny chestnut bugs, or a pile of sea urchins, hence the name of porous structure "chestnut bug" or "sea urchin" which is used by those skilled in the art.

• Volume poreux total compris entre 0,7 et 2 cm³/g,
• % du volume poreux total en pores de diamètre moyen inférieur à 100 Å : entre 0 et 10,
• % du volume poreux total en pores de diamètre moyen compris entre 100 et 1000Å : entre 40 et 90,
• % du volume poreux total en pores de diamètre moyen compris entre 1000 et 5000 Å : entre 5 et 60,
• % du volume poreux total en pores de diamètre moyen compris entre 5000 et 10000 Å : entre 5 et 50,
• % du volume poreux total en pores de diamètre moyen supérieur à 10000 Å : entre 5 et 20.

La surface spécifique mesurée par la méthode B.E.T. de ces catalyseurs est comprise entre 50 et 250 m²/g.The majority of pores consist of the free spaces between the radiating needle plates. These pores, by their nature "wedges", are of continuously variable diameter between 100 and 1000 Å. The network of interconnected macropores results from the space left free between the juxtaposed agglomerates.
These catalysts with a polymodal porosity profile have a porous distribution (determined by the mercury porosimetry technique) preferably characterized as follows:

• Total pore volume of between 0.7 and 2 cm ³ / g,
• % of the total pore volume in pores with an average diameter of less than 100 Å: between 0 and 10,
• % of the total pore volume in pores with a mean diameter of between 100 and 1000Å: between 40 and 90,
• % of the total pore volume in pores with a mean diameter of between 1000 and 5000 Å: between 5 and 60,
• % of the total pore volume in pores with a mean diameter of between 5,000 and 10,000 Å: between 5 and 50,
• % of the total pore volume in pore diameter of greater than 10000 Å: between 5 and 20.

The specific surface area measured by the BET method of these catalysts is between 50 and 250 m ² / g.

The porous structure of "chestnut bug" or "sea urchin" associated with the porous distribution characteristics described above makes it possible to obtain hydrorefining and / or hydroconversion catalysts with very high retention powers, while now an activity in high hydrodemetallation, performance that can not achieve the bimodal catalysts. The reasons are that the "wedge" shape of the mesopores of the "chestnut bug" or "sea urchin" structure offsets or suppresses the concentration gradients of reactants that would normally settle in a cylindrical pore, a phenomenon that adding to a very favorable geometry to oppose the clogging of pore mouths. In addition, each or almost every mesopore has independent access to interstitial macroporosity favoring the homogeneous accumulation of deposits without prematurely deactivating clogging.

These catalysts nevertheless have the disadvantage of being less active in initial activity than the bimodal catalysts on the HDM (hydrodemetallation) functions, HDAC ₇ (hydroconversion of asphaltenes insoluble in n-heptane), HDCCR (hydroconversion of carbon residues quantified by the ConRadson Carbon analysis).

In ebullated hydroconversion processes treating hydrocarbon feedstocks with a high metal content (Ni + V greater than 250 ppm by weight for example), the poorer initial performances of this porous structure catalyst "in a chestnut bug"
or "sea urchin" necessitates a larger amount of daily supplemental catalyst.

For ebullated bed hydroconversion, the catalyst is used in the form of a ball or an extrudate. The "ball" shape allows a more homogeneous bed fluidization and has improved abrasion resistance properties compared to the "extruded" form. The movement of the balls is more homogeneous and the homogeneity of the solids in the bed makes it possible to achieve a good level of metal retention while avoiding segregation phenomena due to gravity. The cut of the ball is also adjustable according to the desired chemical activity in order to minimize the problems related to the diffusion of the molecules in the pores of the catalyst. The metal uptake is considerably increased in bubbling bed relative to the fixed bed.

Similarly, in fixed-bed residue hydrorefining processes, the catalyst with a porous "chestnut horn" or "sea urchin" structure is less efficient (compared to the bimodal catalysts) in terms of initial performances in terms of which concerns HDAC7, HDM, HDCCR functions, although they have a high retention capacity, necessary to treat hydrocarbon feedstocks with high metal contents (Ni + V greater than 40 ppm, for example). The use of this type of catalyst is therefore disadvantageous for the performance of downstream HDS catalysts which are, in fact, poorly protected from asphaltenes, deposition of Ni + V metals and coke.

In the patent application FR 2,534,828 the preparation of catalysts containing one or more metals of groups V, VI and / or VIII and a support of the alumina, silica or silica-alumina type, said support being crushed but when an autoclaving step is carried out in the process, the crushing is operated systematically after it.

Surprisingly, the Applicant has discovered that polymodal catalysts with a "chestnut bug" structure in the form of predominantly irregular and non-spherical alumina agglomerates could be obtained with improved mechanical strength compared with those obtained. by the process of the patent application FR 2,534,828 by changing the position of the crushing step in the steps of the preparation process. This important advantage makes it possible to envisage the use of the catalyst in a bubbling bed reactor whereas it would be impossible for a catalyst obtained by the process of FR 2,534,828 .

In parallel with the reinforced mechanical strength, the catalysts obtained according to the invention make it possible to have optimal performances in terms of HDAsC7, HDM activity, stability and retention capacity for the hydroconversion of heavy hydrocarbon charges containing metals.

DESCRIPTION OF THE INVENTION

The invention relates to a catalyst which can be used for hydrorefining (hydrotreatment) and / or hydroconversion to fixed bed or bubbling bed of heavy hydrocarbon feeds containing metals, having both improved activity, high retention capacity, high stability of performance and high mechanical resistance.
Said catalyst comprises a porous support based on alumina having a porous "chestnut horn" or "sea urchin" structure and characterized by the irregular and non-spherical shape of said support. This is mainly in the form of fragments obtained by crushing alumina beads according to a method defined below.

1. a) granulation à partir d'une poudre d'alumine active présentant une structure mal cristallisée et/ou amorphe, de façon à obtenir des agglomérats sous forme de billes;
2. b) mûrissement en atmosphère humide entre 60 et 100°C puis séchage desdites billes;
3. c) tamisage pour récupérer une fraction desdites billes;
4. d) concassage de ladite fraction;
5. e) calcination d'une partie au moins de ladite fraction concassée à une température comprise entre 250 et 900°C;
6. f) imprégnation acide et traitement hydrothermal à une température comprise entre 80 et 250°C;
7. g) séchage puis calcination à une température comprise entre 500 et 1100°C.

More specifically, the invention relates to a catalyst comprising a support based on alumina, at least one catalytic metal or a group VIB and / or VIII catalytic metal compound, the porous structure of which consists of a plurality of agglomerates juxtaposed and each formed of a plurality of acicular plates, the wafers of each agglomerate being oriented generally radially with respect to each other and with respect to the center of the agglomerate, said support having an irregular and non-spherical shape and presenting itself mainly in the form of fragments obtained by crushing alumina beads, and prepared according to a process including the following steps:

1. a) granulation from an active alumina powder having a poorly crystallized and / or amorphous structure, so as to obtain agglomerates in the form of beads;
2. b) ripening in a humid atmosphere between 60 and 100 ° C and drying said beads;
3. c) sieving to recover a fraction of said beads;
4. d) crushing said fraction;
5. e) calcining at least a portion of said crushed fraction at a temperature between 250 and 900 ° C;
6. f) acid impregnation and hydrothermal treatment at a temperature between 80 and 250 ° C;
7. g) drying and then calcining at a temperature between 500 and 1100 ° C.

The particle size of the support obtained at the end of the process is such that the diameter of the sphere circumscribed at least 80% by weight of said fragments after crushing is between 0.05 and 3 mm. In the case of using the bubbling bed catalyst, said diameter is preferably between 0.1 and 2 mm and very preferably between 0.3 and 1.5 mm. In the case of using the fixed bed catalyst, said diameter is preferably between 1.0 and 2.0 mm.

The active phase of said catalyst contains at least one catalytic metal or a Group VIB catalytic metal compound (group 6 of the new notation of the periodic table of the elements), preferably molybdenum or tungsten, and / or optionally at least one catalytic metal or a group VIII catalytic metal compound (group 8, 9 and 10 of the new notation of the periodic table of the elements), preferably nickel or cobalt. The catalyst may additionally contain at least one doping element chosen from phosphorus, boron, silicon and halogens (group VIIA or group 17 of the new notation of the periodic table of the elements), preferably phosphorus. The silicon deposited on the catalyst, and hence considered as a doping element, is to be distinguished from silicon which may be endogenously present in the initial support. The deposited silicon is quantifiable by use of the Castaing microprobe.
Preferably, the catalyst contains at least one Group VIB metal (preferably molybdenum) and optionally at least one non-noble Group VIII metal, preferably nickel. A preferred catalyst is Ni Mo P.
Without wishing to be bound by any theory, it appears that the improved properties of the catalyst of the present invention are due to improved diffusion of the species within the catalyst grain by the association of the small size of the grains or fragments. , their specific shape leading to an external surface / pollut ratio of higher grain and porosity "in chestnut bug" or "in sea urchin".

The "wedge" shape of the mesopores of the "chestnut bug" or "sea urchin" structure offsets or suppresses the concentration gradients of reagents that would normally occur in a cylindrical pore. The small size of the support grains and their specific shape, irregular and non-spherical, favor the homogeneous entry of the reagents into the macroporosity and on each facet, without clogging of the pore mouths. Finally, the average free path or effective diameter within a grain or fragment is always smaller than the diameter of the sphere circumscribed to said fragment, while it is strictly identical to the diameter in the case of the balls. Despite the irregular shape of the grains or fragments, it is however possible to circumscribe a sphere to each of them and the size of the fragment is defined by the diameter of the sphere circumscribed to said fragment.

At equal size, the specific shape of grains or fragments, irregular and non-spherical, therefore favors intragranular diffusion phenomena. The functions of hydrodemetallation (HDM) and hydroconversion of asphaltenes insoluble in n-heptane (HDAC ₇ ) are increased.

The quantity of Group VIB metal, expressed in% by weight of oxide relative to the weight of the final catalyst, is between 1 and 20%, preferably between 5 and 15%.
The quantity of non-noble group VIII metal, expressed in% by weight of oxide relative to the weight of the final catalyst, can be between 0 and 10%, preferably between 1 and 4%.
The amount of phosphorus, expressed in% by weight of oxide relative to the weight of the final catalyst, may be between 0.3 and 10%, preferably between 1 and 5%, and even more preferably between 1.2 and 4%.
The amount of boron, expressed as% by weight of oxide relative to the weight of the final catalyst, is less than 6%, preferably less than 2%.
The atomic ratio between the phosphorus element and the element of group VIB is advantageously chosen between 0.3 and 0.75.
When at least one doping element is silicon, the silicon content is between 0.1 and 10% by weight of oxide relative to the weight of final catalyst.
When at least one doping element is a halogenated element (group VIIA), the halogen content is less than 5% by weight relative to the weight of final catalyst.

Preparation of the support

1. a) granulation à partir d'une poudre d'alumine active présentant une structure mal cristallisée et/ou amorphe, de façon à obtenir des agglomérats sous forme de billes;
2. b) mûrissement en atmosphère humide entre 60 et 100°C puis séchage desdites billes;
3. c) tamisage pour récupérer une fraction desdites billes;
4. d) concassage de ladite fraction;
5. e) calcination d'une partie au moins de ladite fraction concassée à une température comprise entre 250 et 900°C;
6. f) imprégnation acide et traitement hydrothermal à une température comprise entre 80 et 250°C;
7. g) séchage puis calcination à une température comprise entre 500 et 1100°C.

The alumina-based support has a porous structure consisting of a plurality of juxtaposed agglomerates each formed of a plurality of acicular plates, the wafers of each agglomerate being oriented generally radially relative to each other and by center of the agglomerate, said support having an irregular shape and not spherical and predominantly in the form of fragments obtained by crushing alumina beads, and prepared according to a method including the following steps:

1. a) granulation from an active alumina powder having a poorly crystallized and / or amorphous structure, so as to obtain agglomerates in the form of beads;
2. b) ripening in a humid atmosphere between 60 and 100 ° C and drying said beads;
3. c) sieving to recover a fraction of said beads;
4. d) crushing said fraction;
5. e) calcining at least a portion of said crushed fraction at a temperature between 250 and 900 ° C;
6. f) acid impregnation and hydrothermal treatment at a temperature between 80 and 250 ° C;
7. g) drying and then calcining at a temperature between 500 and 1100 ° C.

1. a) La première étape, dite de granulation, vise à former des agglomérats sensiblement sphériques à partir d'une poudre d'alumine active présentant une structure mal cristallisée et/ou amorphe, selon le procédé tel que décrit dans FR 1 438 497 . Ce procédé consiste à humecter à l'aide d'une solution aqueuse l'alumine active présentant une structure mal cristallisée et/ou amorphe, puis à l'agglomérer dans un granulateur ou drageoir. De manière préférée, un ou plusieurs agents porogènes sont ajoutés lors de la granulation. Les agents porogènes que l'on peut utiliser sont notamment la farine de bois, le charbon de bois, la cellulose, les amidons, la naphtaline et, d'une manière générale tous les composés organiques susceptibles d'être éliminés par calcination.
   On entend par alumine de structure mal cristallisée, une alumine telle que l'analyse aux rayons X donne un diagramme ne présentant qu'une ou quelques raies diffuses correspondant aux phases cristallines des alumines de transition basse température et comportant essentiellement les phases khi, rho, êta, gamma, pseudo-gamma et leurs mélanges. L'alumine active mise en oeuvre est généralement obtenue par déshydratation rapide des hydroxydes d'aluminium tels que la bayérite, l'hydrargillite ou gibbsite, la nordstrandite ou les oxyhydroxydes d'aluminium tels que la boehmite et le diaspore. Cette déshydratation peut être opérée dans n'importe quel appareillage approprié à l'aide d'un courant de gaz chaud. La température d'entrée des gaz dans l'appareillage varie généralement de 400 °C à 1200 °C environ et le temps de contact de l'hydroxyde ou de l'oxyhydroxyde avec les gaz chauds est généralement compris entre une fraction de seconde et 4 à 5 secondes.
   La surface spécifique mesurée par la méthode BET de l'alumine active obtenue par déshydratation rapide d'hydroxydes ou d'oxyhydroxydes varie généralement entre environ 50 et 400 m2/g, le diamètre des particules est généralement compris entre 0,1 et 300 micromètres et de préférence entre 1 et 120 micromètres. La perte au feu mesurée par calcination à 1000 °C varie généralement entre 3 et 15 %, ce qui correspond à un rapport molaire H₂O/Al₂O₃ compris entre environ 0,17 et 0,85.
   Selon un mode de mise en oeuvre particulier, on utilise de préférence une alumine active provenant de la déshydratation rapide de l'hydrate Bayer (hydrargillite) qui est l'hydroxyde d'aluminium industriel facilement accessible et très bon marché; une telle alumine active est bien connue de l'homme de l'art, son procédé de préparation a notamment été décrit dans FR 1 108 011 .
   L'alumine active mise en oeuvre peut être utilisée telle quelle ou après avoir été traitée de façon à ce que sa teneur en soude exprimée en Na₂O soit inférieure à 1000 ppm poids. Par ailleurs, elle contient généralement entre 100 à 1000 ppm poids de silice endogène. L'alumine active mise en oeuvre peut avoir été broyée ou non.
2. b) On procède ensuite à un mûrissement des agglomérats sphériques obtenus en atmosphère humide à température peu élevée, de préférence comprise entre 60 et environ 100°C puis à un séchage généralement opéré entre 100 et 120°C.
3. c) A ce stade, les agglomérats sensiblement sous forme de billes ont une tenue mécanique suffisante pour être tamisés afin de sélectionner la plage granulométrique adaptée selon la granulométrie finale souhaitée. Ainsi, par exemple, pour obtenir un support final dans la plage de taille 0,7-1,4 mm, on tamisera et sélectionnera une fraction de billes dans la plage 1,4-2,8 mm; pour obtenir un support final dans la plage de taille 1-2 mm, on tamisera et sélectionnera une fraction de billes dans la plage 2-4 mm et enfin, pour obtenir un support final dans la plage de taille 2-3 mm, on tamisera et sélectionnera une fraction de billes dans la plage 4-6 mm .
4. d) Ensuite, la fraction de billes dans la plage de tailles sélectionnée est soumise à un concassage. Cette opération est réalisée dans tout type de concasseur connu de l'homme du métier et préférentiellement dans un broyeur à boulet. Elle a une durée comprise entre 5 et 60 minutes et de préférence entre 10 et 30 minutes.
   A l'issue de l'étape de concassage, le support d'alumine se présente majoritairement sous la forme de fragments dont la forme est très irrégulière et non sphérique. Afin de mieux définir la forme obtenue, on peut préciser que les fragments peuvent se présenter sous la forme de billes cassées, sans toutefois avoir de faces de rupture très nettes, ou bien encore sous forme de solides dont la forme géométrique la plus voisine serait un polyèdre irrégulier ne présentant pas forcément de faces planes. Le terme "majoritairement" signifie qu'au moins 50% poids, et de préférence au moins 60% poids des agglomérats sphériques, ont effectivement subi une modification de leur forme lors du concassage, la partie complémentaire représentant les agglomérats sphériques étant restés intacts. En effet, il est bien connu que le concassage étant une opération rustique avec une faible efficacité, il est courant qu'une partie non négligeable des grains ne soient pas concassée.
   Afin d'obtenir une résistance mécanique suffisante du catalyseur final, il est nécessaire que l'étape de concassage soit opérée préalablement à la calcination et au traitement hydrothermal (respectivement étapes e et f).
5. e) Après le concassage, une partie au moins des fragments est calcinée à une température comprise entre environ 250°C et environ 900°C, de préférence entre 500 et 850°C. La partie qui n'est pas calcinée correspond en général aux fines "hors cotes". De manière préférée, on calcine toute la fraction concassée.
6. f) On procède ensuite à une imprégnation acide sur le support suivie d'un traitement hydrothermal selon la méthode décrite dans US 4,552,650 qui peut être appliquée dans son ensemble pour le présent procédé:
   • On traite les agglomérats concassés dans un milieu aqueux comprenant -de préférence constitué d'un mélange d'au moins un acide permettant de dissoudre au moins une partie de l'alumine du support, et au moins un composé apportant un anion capable de se combiner avec les ions aluminium en solution, ce dernier composé étant un individu chimique distinct de l'acide précité,
   • On soumet simultanément ou subséquemment les agglomérats concassés ainsi traités à un traitement hydrothermal (ou autoclavage).
   On entend par acide permettant de dissoudre au moins une partie de l'alumine du support, tout acide qui, mis en contact avec les agglomérats d'alumine active définis ci-dessus, réalise la mise en solution d'au moins une partie des ions aluminium. L'acide dissout au moins 0,5% et au plus 15% en poids de l'alumine des agglomérats. Sa concentration dans le milieu aqueux de traitement est inférieure à 20% en poids et de préférence comprise entre 1% et 15%.
   On utilise de préférence les acides forts tels que l'acide nitrique, l'acide chlorhydrique, l'acide perchlorique, l'acide sulfurique ou des acides faibles comme l'acide acétique, mis en oeuvre à une concentration telle que leur solution aqueuse présente un pH inférieur à environ 4.
   On entend par composé apportant un anion capable de se combiner avec les ions aluminium en solution, tout composé capable de libérer en solution un anion A(-n) susceptible de former avec les cations Al(3+) des produits dans lesquels le rapport atomique n(A/Al) est inférieur ou égal à 3.
   Un cas particulier de ces composés peut être illustré par les sels basiques de formule générale Al2(OH)xAy dans laquelle 0 < x < 6 ; ny < 6 ; n représente le nombre de charges de l'anion A.
   La concentration de ce composé dans le milieu aqueux de traitement est inférieure à 50% en poids et de préférence comprise entre 3% et 30%.
   On utilise de préférence les composés capables de libérer en solution les anions choisis parmi le groupe constitué par les anions nitrate, chlorure, sulfate, perchlorate, chloroacétate, dichloracétate, trichloracétate, bromoacétate, dibromacétate, et les anions de formule générale RCOO(-), dans laquelle R représente un radical pris dans le groupe comprenant H, CH₃, C₂H₅, CH₃CH₂, (CH₃)₂CH.
   Les composés capables de libérer en solution l'anion A(-n) peuvent opérer cette libération, soit directement par exemple par dissociation, soit indirectement par exemple par hydrolyse. Les composés peuvent notamment être choisis parmi le groupe comportant: les acides minéraux ou organiques, les anhydrides, les sels organiques ou minéraux, les esters. Parmi les sels minéraux, on peut citer les sels alcalins ou alcalino-terreux solubles en milieu aqueux, comme ceux de sodium, de potassium, de magnésium ou de calcium, les sels d'ammonium, les sels d'aluminium, les sels de terres rares.
   Ce premier traitement peut être effectué soit par imprégnation à sec des agglomérats, soit par immersion des agglomérats dans la solution aqueuse acide. Par imprégnation à sec, on entend mise en contact des agglomérats d'alumine avec un volume de solution inférieur ou égal au volume poreux total des agglomérats traités.
   Selon un mode particulièrement préféré de mise en oeuvre, on utilise comme milieu aqueux des mélanges d'acide nitrique et acétique ou d'acide nitrique et formique.
   Le traitement hydrothermal est opéré à une température comprise entre environ 80 et environ 250 °C, pendant une période de temps comprise entre environ 5 minutes et environ 36 heures.
   Ce traitement hydrothermal n'entraîne aucune perte d'alumine.
   On opère de préférence à une température comprise entre 120 et 220 °C pendant une période de temps comprise entre 15 minutes et 18 heures.
   Ce traitement constitue un traitement hydrothermal des agglomérats d'alumine active qui réalise la transformation d'au moins une partie de celle-ci en boehmite. Ce traitement hydrothermal (autoclavage) peut être réalisé soit sous pression de vapeur saturante, soit sous une pression partielle de vapeur d'eau au moins égale à 70% de la pression de vapeur saturante correspondant à la température de traitement.
   L'association d'un acide qui permet la dissolution d'au moins une partie de l'alumine et d'un anion qui permet la formation des produits décrits ci-dessus lors du traitement hydrothermal entraîne l'obtention d'une boehmite particulière, précurseur des plaquettes aciculaires du support de l'invention, dont la croissance procède radialement à partir de germes de cristallisation.
   De plus, la concentration de l'acide et du composé dans le mélange de traitement et les conditions de traitement hydrothermal mises en oeuvre sont telles qu'il n'y a pas de perte d'alumine. L'augmentation de la porosité à la suite du traitement est donc due à une expansion des agglomérats au cours du traitement et non à une perte d'alumine.
7. g) Enfin, les agglomérats concassés sont ensuite éventuellement séchés à une température généralement comprise entre environ 100 et 200 °C pendant une période suffisante pour enlever l'eau qui n'est pas chimiquement liée. Les agglomérats sont ensuite soumis à une activation thermique à une température comprise entre environ 500 °C et environ 1100 °C pendant une période comprise entre environ 15 minutes et 24 heures.

The particle size of the support obtained at the end of the process is such that the diameter of the sphere circumscribed at least 80% by weight of said fragments after crushing is between 0.05 and 3 mm. In the case of using the bubbling bed catalyst, said diameter is preferably between 0.1 and 2 mm and very preferably between 0.3 and 1.5 mm.
In the case of using the fixed bed catalyst, said diameter is preferably between 1.0 and 2.0 mm.

1. a) The first step, called granulation, aims to form substantially spherical agglomerates from an active alumina powder having a poorly crystallized structure and / or amorphous, according to the method as described in FR 1 438 497 . This process consists of moistening with active water the active alumina having a poorly crystallized and / or amorphous structure, and then agglomerating it in a granulator or dredger. Preferably, one or more blowing agents are added during granulation. The porogenic agents that can be used include wood flour, charcoal, cellulose, starches, naphthalene and, in general, all organic compounds capable of being removed by calcination.
   The term "alumina" of poorly crystallized structure, an alumina such as X-ray analysis, gives a diagram having only one or a few diffuse lines corresponding to the crystalline phases of the low temperature transition aluminas and essentially comprising the khi, rho, eta, gamma, pseudo-gamma and mixtures thereof. The active alumina used is generally obtained by rapid dehydration of aluminum hydroxides such as bayerite, hydrargillite or gibbsite, nordstrandite or aluminum oxyhydroxides such as boehmite and diaspore. This dehydration can be carried out in any suitable apparatus using a stream of hot gas. The inlet temperature of the gases in the equipment generally varies from about 400 ° C. to about 1200 ° C. and the contact time of the hydroxide or the oxyhydroxide with the hot gases is generally between a fraction of a second and 4 hours. at 5 seconds.
   The specific surface area measured by the BET method of active alumina obtained by rapid dehydration of hydroxides or oxyhydroxides generally varies between approximately 50 and 400 m 2 / g, the particle diameter is generally between 0.1 and 300 micrometers and preferably between 1 and 120 micrometers. The loss on ignition measured by calcination at 1000 ° C. generally varies between 3 and 15%, which corresponds to an H ₂ O / Al ₂ O ₃ molar ratio of between approximately 0.17 and 0.85.
   According to a particular embodiment, an active alumina is preferably used resulting from the rapid dehydration of Bayer hydrate (hydrargillite), which is the industrial aluminum hydroxide that is easily accessible and very inexpensive; such an active alumina is well known to those skilled in the art, its method of preparation has in particular been described in FR 1 108 011 .
   The active alumina used may be used as it is or after having been treated in such a way that its sodium hydroxide content expressed as Na ₂ O is less than 1000 ppm by weight. Moreover, it generally contains between 100 to 1000 ppm by weight of endogenous silica. The active alumina used may have been milled or not.
2. b) The spherical agglomerates obtained in a moist atmosphere are then cured at a low temperature, preferably between 60 and approximately 100 ° C. and then at a drying temperature generally between 100 and 120 ° C.
3. c) At this stage, the agglomerates substantially in the form of beads have sufficient mechanical strength to be screened in order to select the appropriate size range according to the desired final particle size. Thus, for example, to obtain a final support in the size range 0.7-1.4 mm, a bead fraction will be sieved and selected in the range 1.4-2.8 mm; to obtain a final support in the 1-2 mm size range, a bead fraction will be sieved and selected in the 2-4 mm range and finally, to obtain a final support in the 2-3 mm size range, it will be sieved. and select a bead fraction in the 4-6 mm range.
4. d) Next, the bead fraction in the selected size range is subjected to crushing. This operation is carried out in any type of crusher known to those skilled in the art and preferably in a ball mill. It has a duration of between 5 and 60 minutes and preferably between 10 and 30 minutes.
   At the end of the crushing step, the alumina support is predominantly in the form of fragments whose shape is very irregular and non-spherical. In order to better define the shape obtained, it may be specified that the fragments may be in the form of broken beads, without however having very distinct fracture faces, or else in the form of solids whose closest geometric shape would be a irregular polyhedron does not necessarily have flat faces. The term "predominantly" means that at least 50% by weight, and preferably at least 60% by weight of the spherical agglomerates, have actually undergone a change in their shape during crushing, the complementary part representing the spherical agglomerates having remained intact. Indeed, it is well known that crushing being a rustic operation with low efficiency, it is common that a significant portion of the grains are not crushed.
   In order to obtain sufficient mechanical strength of the final catalyst, it is necessary that the crushing step is performed prior to the calcination and the hydrothermal treatment (respectively steps e and f).
5. e) After crushing, at least a portion of the fragments are calcined at a temperature between about 250 ° C and about 900 ° C, preferably between 500 and 850 ° C. The part which is not calcined corresponds in general to the fines "hors cotes". Preferably, the whole crushed fraction is calcined.
6. f) An acid impregnation is then carried out on the support followed by a hydrothermal treatment according to the method described in US 4,552,650 which can be applied as a whole for the present process:
   • The crushed agglomerates are treated in an aqueous medium comprising preferably a mixture of at least one acid for dissolving at least a portion of the alumina of the support, and at least one compound providing an anion capable of combining with the aluminum ions in solution, the latter compound being a chemical individual distinct from the aforementioned acid,
   • The crushed agglomerates thus treated are subjected simultaneously or subsequently to hydrothermal treatment (or autoclaving).
   The term "acid" is used to dissolve at least a portion of the alumina of the support, any acid which, brought into contact with the agglomerates of active alumina defined above, carries out the dissolution of at least a portion of the ions aluminum. The acid dissolves at least 0.5% and at most 15% by weight of the alumina of the agglomerates. Its concentration in the aqueous treatment medium is less than 20% by weight and preferably between 1% and 15%.
   Strong acids such as nitric acid, hydrochloric acid, perchloric acid, sulfuric acid or weak acids, such as acetic acid, are preferably used in a concentration such that their aqueous solution is present. a pH below about 4.
   The term "compound providing an anion capable of combining with aluminum ions in solution" means any compound capable of releasing in solution an A (-n) anion capable of forming, with the Al (3+) cations, products in which the atomic ratio n (A / Al) is less than or equal to 3.
   A particular case of these compounds can be illustrated by the basic salts of general formula Al 2 (OH) x A y in which 0 <x <6; ny <6; n represents the number of charges of anion A.
   The concentration of this compound in the aqueous treatment medium is less than 50% by weight and preferably between 3% and 30%.
   The compounds which are capable of releasing in solution the anions chosen from the group constituted by the anions nitrate, chloride, sulfate, perchlorate, chloroacetate, dichloroacetate, trichloroacetate, bromoacetate, dibromoacetate, and the anions are preferably used. of general formula RCOO (-), wherein R represents a radical taken from the group consisting of H, CH ₃ , C ₂ H ₅ , CH ₃ CH ₂ , (CH ₃ ) ₂ CH.
   The compounds capable of liberating the anion A (-n) in solution can effect this release, either directly, for example, by dissociation or indirectly, for example, by hydrolysis. The compounds may especially be chosen from the group comprising: mineral or organic acids, anhydrides, organic or inorganic salts, esters. Among the inorganic salts, mention may be made of alkali or alkaline earth salts which are soluble in an aqueous medium, such as those of sodium, potassium, magnesium or calcium, ammonium salts, aluminum salts, earth salts rare.
   This first treatment can be carried out either by dry impregnation of the agglomerates, or by immersion of the agglomerates in the acidic aqueous solution. Dry impregnation means contacting the alumina agglomerates with a solution volume less than or equal to the total pore volume of the treated agglomerates.
   According to a particularly preferred mode of implementation, mixtures of nitric and acetic acid or of nitric and formic acid are used as aqueous medium.
   The hydrothermal treatment is operated at a temperature of from about 80 to about 250 ° C for a period of time of from about 5 minutes to about 36 hours.
   This hydrothermal treatment does not cause any loss of alumina.
   It is preferably carried out at a temperature between 120 and 220 ° C for a period of time between 15 minutes and 18 hours.
   This treatment constitutes a hydrothermal treatment of agglomerates of active alumina which carries out the transformation of at least a portion thereof into boehmite. This hydrothermal treatment (autoclaving) can be carried out either under saturated vapor pressure, or under a partial pressure of water vapor at least equal to 70% of the saturated vapor pressure corresponding to the treatment temperature.
   The combination of an acid which allows the dissolution of at least a portion of the alumina and an anion which allows the formation of the products described above during the hydrothermal treatment results in the production of a particular boehmite, precursor of the acicular platelets of the support of the invention, the growth proceeds radially from seed crystals.
   In addition, the concentration of the acid and the compound in the treatment mixture and the hydrothermal treatment conditions used are such that there is no loss of alumina. The increase in porosity as a result of the treatment is therefore due to an expansion of the agglomerates during the treatment and not to a loss of alumina.
7. (g) Finally, the crushed agglomerates are then optionally dried at a temperature generally of between about 100 and 200 ° C for a period sufficient to remove water that is not chemically bonded. The agglomerates are then thermally activated at a temperature of from about 500 ° C to about 1100 ° C for a period of about 15 minutes to 24 hours.

The active alumina support obtained according to the invention, mostly in irregular and non-spherical form, generally has the following characteristics: the loss on ignition measured by calcination at 1000 ° C. is between about 1 and about 15% by weight; Specific range is from about 80 to about 300 m ² / g, their total pore volume is from about 0.45 to about 1.5 cm ³ / g _.

• Une surface spécifique comprise entre 75 et 250 m²/g,
• Une densité de remplissage tassé comprise entre environ 0,35 et 0,80 g/cm³,
• Un volume poreux total ( VPT ) compris entre 0,5 et environ 2,0 cm³/g.
• Une distribution poreuse, déterminée par la technique de porosimétrie au Hg, caractérisée de préférence comme suit :

• % du volume poreux total en pores de diamètre moyen inférieur à 100Å: entre 0 et 10
• % du volume poreux total en pores de diamètre moyen compris entre 100 et 1000Å : entre 40 et 90
• % du volume poreux total en pores de diamètre moyen compris entre 1000 et 5000Å : entre 5 et 60
• % du volume poreux total en pores de diamètre moyen compris entre 5000 et 10000Å : entre 5 et 50
• % du volume poreux total en pores de diamètre moyen supérieur à 10000Å : entre 5 et 20.

The resulting agglomerated agglomerates of active alumina preferably also have the following characteristics:

• A specific surface area of between 75 and 250 m ² / g,
• A packed filling density of between about 0.35 and 0.80 g / cm ³ ,
• A total pore volume (VPT) of between 0.5 and about 2.0 cm ³ / g.
• A porous distribution, determined by the Hg porosimetry technique, preferably characterized as follows:

• % of the total pore volume in pores with an average diameter of less than 100Å: between 0 and 10
• % of the total pore volume in pores with a mean diameter of between 100 and 1000Å: between 40 and 90
• % of the total pore volume in pores with a mean diameter of between 1000 and 5000Å: between 5 and 60
• % of the total pore volume in pores with an average diameter of between 5,000 and 10,000Å: between 5 and 50
• % of the total pore volume in average diameter pore greater than 10000Å: between 5 and 20.

The aforesaid process for preparing the alumina support makes it possible in particular to modify the distribution of the pore volumes according to the pore size of the untreated agglomerates. It makes it possible in particular to increase the proportion of pores between 100 and 1000Å, to reduce the proportion of pores smaller than 100 Å and to reduce the proportion of pores greater than 5000 Å by modifying little the proportion of pores between 1000 and 5000 Å. .
The alumina agglomerates thus obtained may have been thermally stabilized by rare earths, silica or alkaline earth metals as is well known to those skilled in the art. In particular, they can be stabilized according to the process described in US Patent No. 4,061,594.

Depositing the active phase and the doping element (s) on the support obtained

The deposit obtained at the end of step g) is impregnated with at least one solution of at least one catalytic metal and optionally at least one dopant.

The deposition of the active phase in the oxide state and the doping element (s) on the crushed agglomerates of alumina is preferably carried out by the so-called "dry" impregnation method well known to those skilled in the art. The impregnation is very preferably carried out in a single step by a solution containing all the constituent elements of the final catalyst (co-impregnation). Other impregnation sequences can be used to obtain the catalyst of the present invention.
It is also possible to introduce part of the metals, and a part of the dopant element (s), or even all, during the preparation of the support, in particular during the granulation step.

The sources of Group VIB elements that can be used are well known to those skilled in the art. For example, among the sources of molybdenum and tungsten, the oxides, the hydroxides, the molybdic and tungstic acids and their salts can advantageously be used, in particular ammonium salts such as ammonium molybdate, heptamolybdate and ammonium, ammonium tungstate, phosphomolybdic and phosphotungstic acids and their salts, acetylacetonates, xanthates, fluorides, chlorides, bromides, iodides, oxyfluorides, oxychlorides, oxybromides, oxyiodides, carbonyl complexes thiomolybdates, carboxylates. We use preferably the oxides and ammonium salts such as ammonium molybdate, ammonium heptamolybdate and ammonium tungstate.

The sources of Group VIII elements that can be used are known and are, for example, nitrates, sulphates, phosphates, halides, carboxylates such as acetates and carbonates, hydroxides and oxides.

The preferred phosphorus source is orthophosphoric acid, but its salts and esters such as alkaline phosphates, ammonium phosphates, gallium phosphates or alkyl phosphates are also suitable. Phosphorous acids, for example hypophosphorous acid, phosphomolybdic acid and its salts, phosphotungstic acid and its salts may also be advantageously employed. The phosphorus may for example be introduced in the form of a mixture of phosphoric acid and a basic organic compound containing nitrogen such as ammonia, primary and secondary amines, cyclic amines, compounds of the family of pyridine and quinolines and compounds of the pyrrole family.

The source of boron may be boric acid, preferably orthoboric acid H ₃ BO ₃ , biborate or ammonium pentaborate, boron oxide, boric esters. Boron may be introduced for example by a solution of boric acid in a water / alcohol mixture or in a water / ethanolamine mixture.

Many sources of silicon can be used. Thus, it is possible to use ethyl orthosilicate Si (OEt) ₄ , siloxanes, silicones, halide silicates such as ammonium fluorosilicate (NH ₄ ) ₂ SiF ₆ or sodium fluorosilicate Na ₂ SiF ₆ . Silicomolybdic acid and its salts, silicotungstic acid and its salts can also be advantageously employed. The silicon may be added, for example, by impregnation of ethyl silicate in solution in a water / alcohol mixture.

Group VIIA element sources (halogens) that can be used are well known to those skilled in the art. For example, the fluoride anions can be introduced in the form of hydrofluoric acid or its salts. These salts are formed with alkali metals, ammonium or an organic compound. In the latter case, the salt is advantageously formed in the reaction mixture by reaction between the compound organic and hydrofluoric acid. It is also possible to use hydrolysable compounds that can release fluoride anions in water, such as ammonium fluorosilicate (NH ₄ ) ₂ SiF ₆ , silicon tetrafluoride SiF ₄ or sodium tetrafluoride Na ₂ SiF ₆ . The fluorine may be introduced for example by impregnation with an aqueous solution of hydrofluoric acid or ammonium fluoride.

• on laisse reposer le solide humide sous une atmosphère humide à une température comprise entre 10 et 80°C,
• on sèche le solide humide obtenu à une température comprise entre 60 et 150°C,
• on calcine le solide obtenu après séchage à une température comprise entre 150 et 800°C.

Advantageously, after said impregnation of the support, the process for preparing the catalyst of the present invention comprises the following steps:

• the wet solid is allowed to stand under a humid atmosphere at a temperature between 10 and 80 ° C,
• the wet solid obtained is dried at a temperature of between 60 and 150 ° C.
• the solid obtained is calcined after drying at a temperature of between 150 and 800 ° C.

Calcination is not necessary in the case where the impregnating solutions are free of compounds containing the nitrogen element.

Catalyst characteristics

• % du volume poreux total en pores de diamètre moyen inférieur à 100Å : entre 0 et 10
• % du volume poreux total en pores de diamètre moyen compris entre 100 et 1000Å : entre 40 et 90
• % du volume poreux total en pores de diamètre moyen compris entre 1000 et 5000Å : entre 5 et 60
• % du volume poreux total en pores de diamètre moyen compris entre 5000 et 10000Å : entre 5 et 50
• % du volume poreux total en pores de diamètre moyen supérieur à 10000Å : entre 5 et 20.

The porous distribution of the catalyst, determined by the mercury porosity technique, is as follows:

• % of the total pore volume in pores with an average diameter of less than 100Å: between 0 and 10
• % of the total pore volume in pores with a mean diameter of between 100 and 1000Å: between 40 and 90
• % of the total pore volume in pores with a mean diameter of between 1000 and 5000Å: between 5 and 60
• % of the total pore volume in pores with an average diameter of between 5,000 and 10,000Å: between 5 and 50
• % of the total pore volume in average diameter pore greater than 10000Å: between 5 and 20.

The total pore volume of the catalysts according to the invention determined by mercury porosity is between 0.4 and 1.8 g / cm 3.

Preferably, the packed filling density of the catalysts according to the invention is between 0.35 and 0.80 g / cm 3.

Preferably, in the catalysts according to the present invention, the pore diameter at VHg / 2 is between 300 and 700 Å, ie the mean pore diameter, the volume of which in the graphical representation of the distribution porous corresponds to half of the total pore volume, is between 300 and 700 Å, ie 30 to 70 nm.

The catalysts according to the invention have a specific surface area measured by the BET method of between 50 and 250 m ² / g.

• % perte par attrition = 100 (1 - poids de catalyseur de taille supérieure à 850 µm après test/poids de catalyseur de taille supérieure à 850 µm chargé dans le cylindre).

For an implementation of the catalyst according to the invention in bubbling bed, the mechanical strength of the catalyst is critical and is measured by determining the percentage of fines (particles passing through a sieve of 850 microns) produced when the catalyst is set in rotation for a given duration in a cylinder provided with a baffle. At the end of the test, the solid obtained is sieved and the fines are weighed. The attrition loss is quantified according to ASTM D4058-96.
The losses by attrition are then calculated by the following formula:

• % loss by attrition = 100 (1 - weight of catalyst greater than 850 μm after test / weight of catalyst greater than 850 μm loaded in the cylinder).

It is generally accepted by those skilled in the art that a catalyst can only be used in a bubbling bed reactor if the attrition loss measured by this method is less than 5% by weight.
For the catalysts according to the invention, the quantized loss of attrition according to the ASTM D4058-96 standard is less than 5% by weight, and preferably less than or equal to 2% by weight.

For an implementation of the catalyst according to the invention in a fixed bed, the mechanical strength is determined by measuring the compressive strength by the Shell method (ESH), which consists of subjecting a certain quantity of particles and recovering the generated fines. The crush strength corresponds to the force exerted to obtain a level of fines (the fines being the particles passing through a sieve of 425 microns) representing 0.5% of the mass of the particles subjected to the test. The method used, commonly known as the Shell Method, bears the reference "Shell Method Series SMS1471-74" and is implemented by means of a bed crushing apparatus marketed by the company Vinci Technologie under the reference "Bulk crushing strength". SMS ".

Generally, a catalyst can be used in a fixed bed provided that its Shell crush strength is greater than 1.0 MPa.
For the catalysts according to the invention, the crush strength measured by the Shell method is greater than 1.0 MPa, and preferably greater than or equal to 1.5 MPa.

The invention also relates to the process for preparing the catalyst, including the process for preparing the support followed by the impregnation of the support with at least one solution of at least one catalytic metal and optionally a dopant.

Use of the catalyst according to the invention for the hydroconversion / hydrocracking / hydrotreatment of hydrocarbon charges in a bubbling bed

The catalysts according to the invention can be used in a bubbling bed reactor alone or partly in the form of fragments and partly in the form of beads as described in the patent. US 4,552,650 or in the form of cylindrical extrusions.

The feeds may be, for example, atmospheric residues or vacuum residues from direct distillation, deasphalted oils, residues resulting from conversion processes such as, for example, those resulting from coking, from a hydroconversion to a fixed bed, to a bubbling bed. or in a moving bed. These fillers can be used as such or further diluted by a hydrocarbon fraction or a mixture of hydrocarbon fractions which can be chosen, for example, from the products of the FCC process, a light cutting oil (LCO according to the initials of the English name of Light Cycle Oil), a heavy cutting oil (HCO according to the initials of the English name of Heavy Cycle Oil), a decanted oil (OD according to the initials of the Anglo-Saxon denomination of Decanted Oil), a slurry, or possibly derived from distillation, gas oil fractions including those obtained by vacuum distillation called according to the English terminology VGO (Vacuum Gas Oil). The heavy loads can thus include cuts from the coal liquefaction process, aromatic extracts, or any other hydrocarbon cuts.
The heavy feedstocks generally have initial boiling points above 300 ° C., more than 1% by weight of molecules having a boiling point of greater than 500 ° C., a Ni + V metal content of greater than 1 ppm by weight, a asphaltenes content, precipitated in heptane, greater than 0.05%.
In one embodiment, a portion of the converted effluents may be recycled upstream of the unit operating the hydroconversion / hydrotreatment process.

Heavy loads can be mixed with coal in powder form, this mixture is usually called slurry. These charges may be by-products from coal conversion and re-blended with fresh coal. The coal content in the heavy load generally represents and preferably 0.25 by weight (coal / filler) and can vary widely between 0.1 and 1. The coal may contain lignite, be a sub-bituminous coal (according to the English terminology). Saxon), or bituminous. Any type of coal is suitable for the use of the invention, both in a first reactor or in all the reactors operating as a bubbling bed.

In such a process, the catalyst is generally employed at a temperature of between 320 and 470 ° C, preferably 400 to 450 ° C, at a hydrogen partial pressure of about 3 MPa to about 30 MPa, preferably 10 to 20 MPa, at a space velocity of about 0.1 to 10 volumes of filler per volume of catalyst per hour, preferably 0.5 to 2 volumes of filler per volume of catalyst per hour, and with a ratio of hydrogen gas on a hydrocarbon liquid charge of between 100 and 3000 normal cubic meters per cubic meter, preferably 200 to 1200 normal cubic meters per cubic meter.

For the hydroconversion of residues, a particular case of application of the catalyst according to the invention is the use of the catalyst in the presence of coal mixed with the heavy load to be converted. As described in the patents US 4874506 and US 4437973 , the coal in powder form is mixed with a hydrocarbon feedstock richer in hydrogen for be converted to the presence of hydrogen and a supported catalyst. This operation is generally carried out in one or more reactors in series operating in a bubbling bed. The use of the catalyst according to the invention would improve the hydrodynamic behavior of the system as well as the ease of continuous removal of the catalyst. For example, the conversion of coal into liquid is provided by the first reactor and then the HDM and capture impurities is performed at the same time and then a finishing step can be performed using other catalysts.

The catalysts of the present invention are preferably subjected to a sulphurization treatment making it possible, at least in part, to transform the metal species into sulphide before they come into contact with the charge to be treated. This activation treatment by sulphurisation is well known to those skilled in the art and can be performed by any method already described in the literature.

A conventional sulphurization method well known to those skilled in the art consists of heating the mixture of solids under a stream of a mixture of hydrogen and hydrogen sulphide or under a stream of a mixture of hydrogen and hydrocarbons containing sulfur-containing molecules at a temperature between 150 and 800 ° C, preferably between 250 and 600 ° C, generally in a crossed-bed reaction zone.

Process for hydroconversion / hydrocracking / hydrotreatment of fixed bed hydrocarbon feedstocks

The catalysts as described above can also be used in a fixed bed reactor, alone or in part in the form of fragments and partly in the form of beads as described in the patent. US 4,552,650 or in the form of cylindrical extrusions.

The feeds may be, for example, atmospheric residues or vacuum residues from direct distillation, deasphalted oils, residues resulting from conversion processes such as, for example, those resulting from coking, from a hydroconversion to a fixed bed, to a bubbling bed. or in a moving bed. These fillers can be used as such or further diluted by a hydrocarbon fraction or a mixture of hydrocarbon fractions which can be chosen, for example, from the products of the FCC process, a light cutting oil (LCO according to the initials of the English name of Light Cycle Oil), a heavy cutting oil (HCO according to the initials of the English name of Heavy Cycle Oil), a decanted oil (OD according to the initials of the English name of Decanted Oil), a slurry, or which can come from distillation, the gas oil fractions including those obtained by vacuum distillation called according to the English terminology VGO (Vacuum Gas Oil). The heavy loads can thus include cuts from the coal liquefaction process, aromatic extracts, or any other hydrocarbon cuts.
The heavy feedstocks generally have initial boiling points above 300 ° C., more than 1% by weight of molecules having a boiling point of greater than 500 ° C., a Ni + V metal content of greater than 1 ppm by weight, a asphaltenes content, precipitated in heptane, greater than 0.05%.
In one embodiment, a portion of the converted effluents may be recycled upstream of the unit operating the hydroconversion / hydrotreatment process.

In such a process, the catalyst is generally employed at a temperature of between 320 and 450 ° C, preferably 350 to 410 ° C, at a hydrogen partial pressure of about 3 MPa to about 30 MPa, preferably 10 to 20 MPa, at a space velocity of about 0.05 to 5 volumes of filler per volume of catalyst per hour, preferably 0.2 to 0.5 volumes of filler per volume of catalyst per hour, and with a ratio of hydrogen gas on a hydrocarbon liquid charge of between 200 and 5000 normal cubic meters per cubic meter, preferably 500 to 1500 normal cubic meters per cubic meter.

The catalysts used in the present invention are preferably subjected to a sulphurization treatment making it possible, at least in part, to convert the metal species into sulphide before they come into contact with the charge to be treated. This activation treatment by sulphurisation is well known to those skilled in the art and can be performed by any method already described in the literature.

A conventional sulphurization method well known to those skilled in the art consists of heating the mixture of solids under a stream of a mixture of hydrogen and hydrogen sulphide or under a stream of a mixture of hydrogen and hydrocarbons containing sulfur-containing molecules at a temperature between 150 and 800 ° C, preferably between 250 and 600 ° C, generally in a crossed-bed reaction zone.

The following examples illustrate the invention described in this patent without limiting its scope.

Example 1 Preparation of Crushed Alumina Agglomerates According to the Invention

The raw material is alumina obtained by very rapid decomposition of hydrargillite in a hot air stream (T = 1000 ° C). The product obtained consists of a mixture of transition aluminas: aluminas (chi) and (rho). The specific surface of this product is 300 m ² / g and the loss on ignition (PAF) of 5%.
The alumina is (after grinding) in the form of a powder whose average particle diameter is 7 microns.
This alumina is mixed with wood flour as pore-forming (15% by weight) and then shaped in a granulator or bezel for a time adapted to the desired particle size. The agglomerates obtained are subjected to a curing stage by passing steam at 100 ° C. for 24 hours and then dried. They are sieved then crushed and finally calcined.
These beads are then impregnated dry with a solution containing, for example, a mixture of nitric acid and acetic acid in aqueous phase in an impregnating barrel. Once impregnated, they are introduced into an autoclave for approximately 2 hours, at a temperature of 210 ° C. under a pressure of 20.5 bar.

On leaving the autoclave, crushed agglomerates of alumina according to the invention are obtained which are dried for 4 hours at 100 ° C. and calcined for 2 hours at 650 ° C.
The agglomerates have a size of between 1 and 1.5 mm. Their pore volume is equal to 0.95 cm ³ / g with a multimodal porous distribution. The specific surface of the support is 130 m ² / g.

Example 2 Preparation of Alumina Balls (Not in Accordance with the Invention)

A catalyst is prepared in the form of beads according to the procedure of Example 1 with the exception of the crushing step.

The beads having a particle size of between 1.4 and 2.8 mm are selected.

Example 3 Preparation of Crushed Alumina Agglomerates According to the Invention

The support of this example is prepared in the same way as that of Example 1, but the granulation times and the sieving-crushing steps are modified so as to obtain agglomerates of size between 1.4 and 2.8. mm.

Example 4 Preparation of Alumina Agglomerates (not in Accordance with the Invention )

A catalyst is prepared in the form of beads according to the procedure of Example 1 with the exception of the crushing step which is carried out after autoclaving.
On leaving the autoclave, after the drying (4 h, 100 ° C.) and calcination (2 h, 650 ° C.) steps, the balls are crushed so as to obtain a 1.4-2.8 mm fraction.

EXAMPLE 5 Preparation of catalysts A, B, C and D from the supports of Examples 1, 2, 3, 4

The supports of Examples 1, 2, 3, 4 were dry impregnated with an aqueous solution containing molybdenum and nickel salts and phosphoric acid. The molybdenum precursor is MoO ₃ molybdenum oxide and that of nickel is Ni (CO ₃ ) nickel carbonate. After maturing at room temperature in an atmosphere saturated with water, the impregnated supports are dried overnight at 120 ° C. and then calcined at 500 ° C. for 2 hours under dry air. The final content of molybdenum trioxide is 9.4% by weight of the finished catalyst. The final nickel oxide NiO content is 2% by weight of the finished catalyst. The final content of phosphorus oxide P ₂ O ₅ is 2% by weight of the finished catalyst.
The textural and physico-chemical characteristics of the catalysts A, B, C and D respectively from the supports of Examples 1, 2, 3 and 4 are reported in Table 1. Table 1 Catalyst AT B VS D MoO ₃ (% wt) 9.4 9.4 9.4 9.4 NiO (% wt) 2.0 2.0 2.0 2.0 P ₂ O ₅ (% wt) 2.0 2.0 2.0 2.0 SiO ₂ (% wt) - - - Ni / Mo (at / at) 0.40 0.40 0.40 0.40 P / Mo (at / at) 0.42 0.42 0.42 0.42 dMo (at / nm ² ) 3.8 3.8 3.8 3.8 DRT (g / cm3) 0.55 0.52 0.51 0.52 S _BET (m ² / g) 97 105 103 100 VPT Hg (cm ³ / g) 0.80 0.95 0.90 0.90 dp to VHg / 2 (Å) 350 380 370 370 V Hg> 500 Å (cm ³ / g) 0.35 0.44 0.40 0.40 V Hg> 1000 Å (cm ³ / g) 0.26 0.30 0.28 0.28

Example 6 Comparison of Mechanical Attrition Resistances of Catalysts A, B, C, D for Use in a Bubbling Bed

The mechanical strength with respect to the attrition of the catalysts A, B, C and D was determined according to the method presented in the description.
Table 2 below presents the results obtained for the catalysts A, B, C, D. Catalyst AT B VS D % fine produced after attrition (weight) 1.5% 2% 2% 12%

Catalyst D is therefore not usable in bubbling bed because the rate of fines generated after the attrition test is well above 5% by weight.

Example 7 Comparison of the Hydroconversion Performance of Residual Bubble Bed.

The performances of catalysts A (according to the invention), B (non-compliant) and C (according to the invention) were compared during a pilot test in a pilot unit comprising a tubular reactor equipped with a device allowing the keeping the catalyst in constant boiling inside the reactor. The pilot unit implemented work is representative of an industrial unit H-OIL ^® of residue hydroconversion ebullated bed described in numerous patents, e.g. US 4521295 and US 4495060 .

The pilot reactor is charged with 1 liter of catalyst.
The oiling of the unit is carried out using a vacuum distillation gas oil, or DSV, whose characteristics are reported in Table 3. Table 3 Charge DSV RSV
Safaniya RA
Boscan Spec. grav. .9414 1.0457 1,023 Sulfur (% wt) 2.92 5.31 5.5 Nitrogen (ppm wt) 1357 4600 5800 Viscosity (cSt) 13.77 5110 1380 Temp. viscosity (° C) 100 100 100 Viscosity (cSt) 38.64 285 120 Temp. viscosity (° C) 70 150 150 C. Conradson (% wt) 23.95 16.9 Asphalt. C7 (% weight) 14.5 14.0 Ni (ppm wt) <2 52 125 V (ppm wt) 3.3 166 1290 D1160: PI ° C 361 496 224 D1160: 05% vol. ° C 416 536 335 D1160: 10% vol. ° C 431 558 402 D1160: 20% vol. ° C 452 474 D1160: 30% vol. ° C 467 523 D1160: 40% vol. ° C 479 566 D1160: 50% vol. ° C 493 D1160: 60% vol. ° C 507 D1160: 70% vol. ° C 522 D1160: 80% vol. ° C 542 D1160: 90% vol. ° C 568 D1160: 95% vol. ° C 589 D1160: PF ° C 598 558 566

$$\mathrm{HDM}\left(\mathrm{\%}\mathrm{pds}\right)\mathrm{=}\left(\left(\mathrm{ppm\; pds\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\mathrm{-}\left(\mathrm{ppm\; pds\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{recette}\right)\mathrm{/}\left(\left(\mathrm{ppm\; pds\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

The temperature is increased to 343 ° C and the test load, a vacuum distillation residue Safaniya type (RSV), is injected. The reaction temperature is then raised to 410 ° C. The hydrogen flow rate is 600 l / l, the space velocity is 0.3 l / l / h.
The conditions of the test are fixed in isotherm, which makes it possible to measure the deactivation of the catalyst by the direct comparison of the performances at different ages. The ages are expressed here in m ³ of feedstock / kg of catalyst (m ³ / kg) which represents the cumulative amount of feedstock passed over the catalyst based on the weight of catalyst charged.
Performance in conversion, HDM are defined as follows: $$\mathrm{Conversion}\left(\%w\right)=\left(\left(\%\mathrm{wt\; of}550\mathrm{°\; C}+\right)\mathrm{charge}-\left(\%w550\mathrm{°\; C}+\right)\mathrm{recipe}\right)/\left(\left(\%w550\mathrm{°\; C}+\right)\mathrm{charge}\right)*100$$

$$\mathrm{HDM}\left(\mathrm{\%}w\right)\mathrm{=}\left(\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\mathrm{-}\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{recipe}\right)\mathrm{/}\left(\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

The charge is then changed by passing through Boscan atmospheric residue. This charge makes it possible to evaluate the metal retention of the catalyst. The conduct of the test aims to maintain an HDM rate between 80 and 60%. For this, the reaction temperature is maintained at 410 ° C. The test is stopped when the HDM rate drops below 60%. The conversion is maintained between 50 and 60 wt% to obtain good fuel stability. To evaluate the stability of the products formed, a measurement according to the "P value" method is performed on the 350 ° C + fraction of the effluent recovered after testing.

Table 4 compares the performance of catalysts A, B and C at the beginning of the test (0.56 m ³ / kg) and at the end of the test (1.44 m ³ / kg).

Catalyst D could not be evaluated, even in terms of initial activity because the production of tip fines of the second day of testing (Age <0.17 m ³ / kg) led to operating problems (clogging, emergence of pressure gradients) and when the unit stops. Table 4 Catalyst + Age Conv (% wt) HDM (% wt) Metal retention (% wt) P value Shell At 0.56 m ³ / kg, RSV Saf 55 72 9.5 1.6 B at 0.56 m ³ / kg RSV Saf 54 55 8.1 1.4 C at 0.56 m ³ / kg, RSV Saf 54 65 8.7 1.5 A at 1.44 m ³ / kg RA Boscan 55 80 120 1.4 B at 1.44 m ³ / kg RA Boscan 56 70 100 1.2 C at 1.44 m ³ / kg RA Boscan 55 78 115 1.3

The HDM catalysts supported on crushed agglomerates according to the invention exhibit improved initial HDM properties and greater stability. The performances in HDM are all the higher as the size of the agglomerates is low.

Example 8 Comparison of Fixed Bed Mechanical Resistance of Catalysts A, B, C, D

Table 5 below presents the results obtained for fixed bed crushing measurements carried out according to the method described in the description for catalysts A, B, C, D. Catalyst AT B VS D Pressure exerted for 0.5% weight of fines 1.8 MPa 1.7 MPa 1.7 MPa 0.8 MPa

The Shell crush strength value for catalyst D is not compatible with use in a fixed bed residue hydroconversion process, which value is less than 1 MPa.

Example 9 Comparison of the Performance in Fixed Bed Residue Hydroconversion for Catalysts A, B and C.

The performances of the catalysts A (compliant), B (non-compliant) and C (compliant) previously described were compared during a fixed bed pilot test of hydrotreatment of different petroleum residues. An atmospheric residue (RA) of Middle East origin (Arabian Light) followed by an atmospheric residue of Venezuelan extra heavy crude (Boscan) is treated first. These two residues are characterized by high viscosities, high levels of Conradson carbon and asphaltenes. The Boscan RA also contains very high levels of nickel and vanadium.

The characteristics of these residues are shown in Table 6: Table 6 RA Arabian Light RA Boscan Density 15/4 .9712 1,023 Viscosity at 100 ° C mm ² / s 161 1380 Viscosity at 150 ° C mm ² / s 45 120 Sulfur % wt 3.38 5.5 Nitrogen ppm 2257 5800 Nickel ppm 12 125 Vanadium ppm 41 1290 Iron ppm 1 8 Carbon % wt 84.8 83.40 Hydrogen % wt 11.1 10,02 Aromatic carbon % 24.8 29.0 Molecular weight g / mol 528 730 Conradson Carbon % wt 10.2 16.9 Asphaltenes C5 % wt 6.4 24.1 Asphaltenes C7 % wt 3.4 14.9 SARA % wt saturated % wt 28.1 8.7 aromatic % wt 46.9 35.0 resins % wt 20.1 34.0 asphaltenes % wt 3.5 14.6 Simulated distillation PI ° C 296 224 5% ° C 400 335 10% ° C 422 402 20% ° C 451 474 30% ° C 474 523 40% ° C 502 566 50% ° C 536 60% ° C 571 70% ° C 80% ° C 90% 95% PF ° C 571 566

The tests were conducted in a pilot hydroprocessing unit comprising a fixed-bed tubular reactor. The reactor is filled with 1 liter of catalyst. Fluid flow (residue + hydrogen) is upward in the reactor. This type of pilot unit is representative of the operation of one of the reactors of the HYVAHL unit of IFP for the hydroconversion of residues into fixed beds.

After a sulphurization step by circulation in the reactor of a gas oil cup containing dimethyl disulphide at a final temperature of 350 ° C., the unit is operated for 300 hours with the Arabian Light Atmospheric Residue at 370 ° C., 150 bar of total pressure using a VVH of 0.5 I load / l cat / h. The flow rate of hydrogen is such that it respects the ratio 1000 l / l of load. The conditions of the RAAL test are fixed in isotherm, which makes it possible to measure the initial deactivation of the catalyst by the direct comparison of the performances at different ages. The ages are expressed in operating hours under Arabian Light atmospheric residue, the zero time being taken upon arrival at the test temperature (370 ° C).

$$\mathrm{HDAsC}\mathrm{7}\left(\mathrm{\%}\mathrm{pds}\right)\mathrm{=}\left(\left(\mathrm{\%}\mathrm{pds\; Asphaltènes\; insolubles\; dans\; le\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{charge}\mathrm{-}\left(\mathrm{\%}\mathrm{pds\; Asphaltènes\; insolubles\; dans\; le\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{recette}\right)\mathrm{/}\left(\left(\mathrm{\%}\mathrm{pds\; Asphaltènes\; insolubles\; dans\; le\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

$$\mathrm{HDCCR}\left(\mathrm{\%}\mathrm{pds}\right)\mathrm{=}\left(\left(\%\mathrm{pds\; CCR}\right)\mathrm{charge}\mathrm{-}\left(\%\mathrm{pds\; CCR}\right)\mathrm{recette}\right)\mathrm{/}\left(\left(\%\mathrm{pds\; CCR}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

HDM, HDAsC7 and HDCCR performance are defined as follows: $$\mathrm{HDM}\left(\mathrm{\%}w\right)\mathrm{=}\left(\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\mathrm{-}\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{recipe}\right)\mathrm{/}\left(\left(\mathrm{ppm\; wt\; Ni}\mathrm{+}\mathrm{V}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

$$\mathrm{HDAsC}\mathrm{7}\left(\mathrm{\%}w\right)\mathrm{=}\left(\left(\mathrm{\%}\mathrm{Asphaltenes\; insoluble\; in\; the\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{charge}\mathrm{-}\left(\mathrm{\%}\mathrm{Asphaltenes\; insoluble\; in\; the\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{recipe}\right)\mathrm{/}\left(\left(\mathrm{\%}\mathrm{Asphaltenes\; insoluble\; in\; the\; n}\mathrm{-}\mathrm{heptane}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

$$\mathrm{HDCCR}\left(\mathrm{\%}w\right)\mathrm{=}\left(\left(\%\mathrm{CCR}\right)\mathrm{charge}\mathrm{-}\left(\%\mathrm{CCR}\right)\mathrm{recipe}\right)\mathrm{/}\left(\left(\%\mathrm{CCR}\right)\mathrm{charge}\right)\mathrm{*}\mathrm{100}$$

Table 7 compares the HDM, HDAsC7 and HDCCR performances of catalysts A, B and C at the start of the test (50 hours) and at the end of the test (300 hours). Table 7 Catalyst + Age HDM HDAsC7 HDCCR (% wt) (Wt%) (% wt) A at 50 hours 90 91 50 B at 50 hours 83 85 40 C to 50 hours 87 88 46 At 300 hours 85 86 44 B to 300 hours 74 75 32 C at 300 hours 83 83 39

The charge is then changed by passing through Boscan atmospheric residue. The conduct of the test aims to maintain a constant HDM level around 80% weight throughout the cycle. For this, the deactivation of the catalyst is compensated by a gradual increase in the reaction temperature. The test is stopped when the reaction temperature reaches 420 ° C., which temperature is considered as representative of the end-of-cycle temperature of an industrial plant for hydrorefining residues.

Table 8 compares the amounts of nickel + vanadium from the Boscan RA deposited on the 3 catalysts. Table 8 Catalyst Ni + V deposited (% of the fresh catalyst mass) Catalyst A 97 Catalyst B 85 Catalyst C 91

It appears that the HDM catalysts supported on agglomerates according to the invention lead to initial performances on RAAL and retention on RAB higher than those of the catalyst supported on beads; the gains in performance and retention being all the more important that agglomerates are small.

Claims (28)

1. A catalyst comprising an alumina-based support, at least one catalytic metal or compound of a catalytic metal from group VIB and/or VIII, the pore structure of which is composed of a plurality of juxtaposed agglomerates and each formed by a plurality of acicular platelets, the platelets of each agglomerate generally being oriented radially with respect to the others and with respect to the centre of the agglomerate, said support having an irregular and non-spherical shape and being mainly in the form of fragments obtained by crushing alumina beads, and prepared using a process including the following steps:

   a) granulation starting from an active alumina powder having a low crystallinity and/or amorphous structure, to obtain agglomerates in the form of beads;

   b) maturing in a moist atmosphere between 60°C and 100°C then drying said beads;

   c) sieving to recover a fraction of said beads;

   d) crushing said fraction;

   e) calcining at least a portion of said crushed fraction at a temperature in the range 250°C to 900°C;

   f) impregnating with acid and hydrothermal treatment at a temperature in the range 80°C to 250°C;

   g) drying then calcining at a temperature in the range 500°C to 1100°C.
2. A catalyst according to claim 1, in which the loss on attrition, quantified in accordance with the ASTM D4058-96 standard, is less than 5% by weight.
3. A catalyst according to claim 2, in which the loss on attrition, quantified in accordance with the ASTM D4058-96 standard, is less than 2% by weight.
4. A catalyst according to claim 1, in which the crush strength, measured using the Shell method in accordance with standard SMS 1471-74, is 1.5 MPa or more.
5. A catalyst according to claim 1, in which granulation step a) uses at least one pore-forming agent.
6. A catalyst according to one of the preceding claims, comprising at least one catalytic metal or a compound of a catalytic metal from group VIB.
7. A catalyst according to one of the preceding claims, comprising at least one catalytic metal or a compound of a catalytic metal from group VIII (columns 8, 9 and 10 of the new periodic table notation).
8. A catalyst according to one of the preceding claims, further containing at least one doping element selected from the group constituted by phosphorus, boron, silicon and the halogens.
9. A catalyst according to one of the preceding claims, wherein the support in the form of fragments has a size such that the diameter of the sphere circumscribing at least 80% of said fragments is in the range 0.05 to 3 mm.
10. A catalyst according to claim 9, in which the diameter of the circumscribing sphere is in the range 0.3 to 1.5 mm for an ebullated bed implementation.
11. A catalyst according to claim 9, in which the diameter of the circumscribing sphere is in the range 1.0 to 2.0 mm for a fixed bed implementation.
12. A catalyst according to one of the preceding claims, in which the amount of group VIB metal, expressed as the % by weight of oxide with respect to the final catalyst weight, is in the range 1% to 20% and in which the amount of group VIII metal, expressed as the % by weight of oxide with respect to the final catalyst weight, is in the range 0 to 10%.
13. A catalyst according to claim 12, in which the group VIB metal is molybdenum and the group VIII metal is nickel.
14. A catalyst according to one of the preceding claims, in which the amount of non noble group VIII metal is in the range 1% to 4% by weight.
15. A catalyst according to one of the preceding claims, in which the doping element is phosphorus and the amount of phosphorus, expressed as a % by weight of oxide with respect to the final catalyst weight, is in the range 0.3% to 10%.
16. A catalyst according to claim 15, in which the amount of phosphorus is in the range 1.2% to 4% by weight.
17. A catalyst according to one of the preceding claims, further containing at least one doping element selected from the group formed by boron, silicon and the halogens in amounts, expressed as the % by weight of oxide with respect to the final catalyst weight, of less than 6% for boron, less than 5% for the halogens and in the range 0.1 % to 10% for silicon.
18. A catalyst according to one of the preceding claims, in which the pore distribution, determined by the Hg porosimetry technique, is characterized as follows:

    • % of total pore volume as pores with a mean diameter of less than 100 Å: between 0 and 10

    • % of total pore volume as pores with a mean diameter between 100 and 1000Å: between 40 and 90

    • % of total pore volume as pores with a mean diameter between 1000 and 5000 Å: between 5 and 60

    • % of total pore volume as pores with a mean diameter between 5000 and 10000 Å: between 5 and 50

    • % of total pore volume as pores with a mean diameter of more than 10000 Å: between 5 and 20.
19. A catalyst according to one of the preceding claims, in which the settled packing density is in the range 0.35 to 0.80 g/cm³ and the total pore volume, determined by mercury porosimetry, is in the range 0.4 to 1.8 g/cm³.
20. A catalyst according to one of the preceding claims, in which the pore diameter at VHg/2 is in the range 300 to 700 Å.
21. A catalyst according to one of the preceding claims in which, in granulation step a), the active alumina is moistened using an aqueous solution then agglomerated in a granulator.
22. A catalyst according to one of the preceding claims, in which in step f), the crushed fraction is impregnated with an aqueous solution comprising at least one acid which can dissolve at least a portion of the alumina of the support, and at least one compound, distinct from said acid, supplying an anion which is capable of combining with aluminium ions in solution.
23. A catalyst according to one of the preceding claims, wherein the support obtained at the end of step g) is impregnated with at least one solution of at least one catalytic metal and optionally at least one dopant.
24. A catalyst according to claim 23, wherein after impregnation of the support, the moist solid is left in a moist atmosphere at a temperature in the range 10°C to 80°C, the moist solid obtained is dried at a temperature in the range 60°C to 150°C and the solid obtained is calcined after drying at a temperature in the range 150°C to 800°C.
25. A process for hydrotreating and/or hydroconverting heavy metal-containing hydrocarbon feeds using a catalyst according to one of the preceding claims.
26. A process according to claim 25, in which said catalyst is employed in ebullated bed mode at a temperature in the range 320°C to 470°C, at a partial pressure of hydrogen of between 3 MPa and 30 MPa, at a space velocity of about 0.1 to 10 volumes of feed per volume of catalyst per hour, and with a ratio of gaseous hydrogen to liquid hydrocarbon feed in the range 100 to 3000 normal cubic metres per cubic metre.
27. A process according to claim 25, in which said catalyst is employed in fixed bed mode at a temperature in the range 320°C to 450°C, at a partial pressure of hydrogen of between 3 MPa and 30 MPa, at a space velocity of about 0.05 to 5 volumes of feed per volume of catalyst per hour, and with a ratio of gaseous hydrogen to liquid hydrocarbon feed in the range 200 to 5000 normal cubic metres per cubic metre.
28. A process according to claim 23, in which said catalyst is used partly in the form of fragments and partly in the form of beads or in the form of cylindrical extrudates.